'use strict'
const path = require('path')
const defaultSettings = require('./src/settings.js')

function resolve(dir) {
    return path.join(__dirname, dir)
}

const name = defaultSettings.title || 'vue Admin Template' // page title

// If your port is set to 80,
// use administrator privileges to execute the command line.
// For example, Mac: sudo npm run
// You can change the port by the following methods:
// port = 9528 npm run dev OR npm run dev --port = 9528
const port = process.env.port || process.env.npm_config_port || 9528 // dev port

// 判断当前所在的环境 如果环境变量从 .env.development 拿出来的, 就证明是开发环境
const isDev = process.env.ENV === 'development'
    // 默认情况下, 既不排除任何包, 也不引入任何 cdn
let externals = {}
let jsCDN = []

if (!isDev) {
    // 判断到当前实在非开发环境, 追加排除的包以及远程cdn地址
    // 配置排除打包的对象
    // 里面的属性是以 key: value 键值对形式指定
    // 需要被排除的包名: 排除以后再全局可以替代的变量名
    externals = {
        // 'jQuery': '$',
        'vue': 'Vue',
        'element-ui': 'ELEMENT',
        'xlsx': 'XLSX'
    }

    // 创建数组管理要引入的 cdn 地址
    jsCDN = [
        'https://cdn.bootcdn.net/ajax/libs/vue/2.6.14/vue.min.js',
        'https://cdn.bootcdn.net/ajax/libs/element-ui/2.15.7/index.min.js',
        'https://cdn.bootcdn.net/ajax/libs/xlsx/0.17.4/xlsx.min.js'
    ]
}

// All configuration item explanations can be find in https://cli.vuejs.org/config/
module.exports = {
    // 指定需要一并处理的依赖包(默认情况下 node_modules 里面的库不会被处理)
    transpileDependencies: ['screenfull'],
    /**
     * You will need to set publicPath if you plan to deploy your site under a sub path,
     * for example GitHub Pages. If you plan to deploy your site to https://foo.github.io/bar/,
     * then publicPath should be set to "/bar/".
     * In most cases please use '/' !!!
     * Detail: https://cli.vuejs.org/config/#publicpath
     */
    publicPath: '/',
    outputDir: 'dist',
    assetsDir: 'static',
    lintOnSave: process.env.NODE_ENV === 'development',
    productionSourceMap: false,
    devServer: {
        port: port,
        open: true,
        overlay: {
            warnings: false,
            errors: true
        },
        // 这里可以配置代理设定
        proxy: {
            // key: value 的形式拽定 需要转发的url模式: 转发的目的地
            '/api': {
                target: 'http://ihrm-java.itheima.net',
                changeOrigin: true
            }
        }
    },
    configureWebpack: {
        // provide the app's title in webpack's name field, so that
        // it can be accessed in index.html to inject the correct title.
        name: name,
        resolve: {
            alias: {
                '@': resolve('src')
            }
        },
        externals
    },
    chainWebpack(config) {
        // 拦截html的生成, 在参数中添加 cdn 数组
        config.plugin('html').tap(args => {
            args[0].jsCDN = jsCDN
            return args
        })

        // it can improve the speed of the first screen, it is recommended to turn on preload
        config.plugin('preload').tap(() => [{
            rel: 'preload',
            // to ignore runtime.js
            // https://github.com/vuejs/vue-cli/blob/dev/packages/@vue/cli-service/lib/config/app.js#L171
            fileBlacklist: [/\.map$/, /hot-update\.js$/, /runtime\..*\.js$/],
            include: 'initial'
        }])

        // when there are many pages, it will cause too many meaningless requests
        config.plugins.delete('prefetch')

        // set svg-sprite-loader
        config.module
            .rule('svg')
            .exclude.add(resolve('src/icons'))
            .end()
        config.module
            .rule('icons')
            .test(/\.svg$/)
            .include.add(resolve('src/icons'))
            .end()
            .use('svg-sprite-loader')
            .loader('svg-sprite-loader')
            .options({
                symbolId: 'icon-[name]'
            })
            .end()

        config
            .when(process.env.NODE_ENV !== 'development',
                config => {
                    config
                        .plugin('ScriptExtHtmlWebpackPlugin')
                        .after('html')
                        .use('script-ext-html-webpack-plugin', [{
                            // `runtime` must same as runtimeChunk name. default is `runtime`
                            inline: /runtime\..*\.js$/
                        }])
                        .end()
                    config
                        .optimization.splitChunks({
                            chunks: 'all',
                            cacheGroups: {
                                libs: {
                                    name: 'chunk-libs',
                                    test: /[\\/]node_modules[\\/]/,
                                    priority: 10,
                                    chunks: 'initial' // only package third parties that are initially dependent
                                },
                                elementUI: {
                                    name: 'chunk-elementUI', // split elementUI into a single package
                                    priority: 20, // the weight needs to be larger than libs and app or it will be packaged into libs or app
                                    test: /[\\/]node_modules[\\/]_?element-ui(.*)/ // in order to adapt to cnpm
                                },
                                commons: {
                                    name: 'chunk-commons',
                                    test: resolve('src/components'), // can customize your rules
                                    minChunks: 3, //  minimum common number
                                    priority: 5,
                                    reuseExistingChunk: true
                                }
                            }
                        })
                        // https:// webpack.js.org/configuration/optimization/#optimizationruntimechunk
                    config.optimization.runtimeChunk('single')
                }
            )
    }
}